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Are new data center cabinets too heavy for the floor?

We built a data center several years ago and are refreshing the IT equipment in it. Should I worry about how big and heavy my new cabinets will be for the existing structure?

Structural analysis is a very complex field of engineering. There's a lot you can figure out yourself, but beyond simple verifications, it's not an amateur's game.

The answer varies depending on whether you have a raised or leveled floor. Older data centers typically use raised floors.

If you're concerned with how heavy your new data center cabinets will be, first verify the cabinet's loading capacities. When data center cabinets are overloaded, the floor typically is, as well.

If you have a raised-access floor, get the manufacturer's structural characteristics. Structural specifications are listed in various units: pounds per square foot (or metric units), total capacity of the four-square-foot tile, pounds per square inch for point loading (where the cabinet's wheels or leveling feet sit), and total rolling loads for ten or ten thousand wheel passes. The rolling load capacity can even be based on different wheel sizes. The flooring manufacturer can help if you tell it the sizes and types of cabinets you're using, so have their number available.

Your major concern -- raised floor or not -- is the building structure. Was the building designed for the specific capacity of the raised floor? Consult with the facilities team or contact the data center architect that designed the floor to find out. Even if your floor system isn't strong enough for your newer data center cabinets, you can usually add extra supporting pedestals under tiles where the cabinet wheels or leveling feet sit. If you have to add pedestals to under-rated tiles, if the raised floor is stronger than the floor slab, or if you're just close to limits, a licensed structural engineer should evaluate.

Without a raised floor, find out the floor slab design capacity, both for static and live loads.

Focus on the live load to determine whether your layout and cabinet weights will be safe. If you are close to the limits -- if the slab is rated at less than 100 pounds per square foot -- engage a structural engineer to verify. The engineer can explain how to accommodate the load.

Structural failures are serious business -- they are dangerous and extremely expensive. Floors are designed to deflect a small amount under full-rated load. A raised floor can be leveled to compensate for the deflection, but that doesn't solve the problem. If you're at the limit, adding more weight could result in structural failure.

Most floors support the majority of cabinets in use today -- cabinets are large and separated by wide aisles, spreading the load of, for example, a heavy storage array and some dense blade servers, across the floor area. But when dealing with smaller cabinets (24" wide by 36" deep, for example) and compressed aisles to fit more equipment, you should have the structure examined before adding more weight.

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What's the heaviest cabinet in your data center? Storage array, blade servers or something else?
Excellent Article for those who are new to Data Centre Management and have taken over a legacy Data Centre that is moving towards Virtualisation ,the new storage arrays and real time flash devices that whilst only being 3u's high can certainly be packed in a rack leaving you with one heavy beast.  Even if your floor weightings can't support some of these heavier beasts there is plenty you can do to re-inforce the floor and spread the weight but as Robert says get your facilities involved to structurally work out what needs to be done.  You DON'T want to think you've got it right to find the cab has dropped through your raised floor and cracked the concrete slab below, especially if you are on the first floor like I am!  I wish there had been forums and Tech sites available when I started managing our Data Centres 10 years ago could have saved myself a whole lot of headaches.
It seems to me if your flight can't handle 100 pounds per square foot, you're going to have trouble with it holding things like sysadmins, let alone equipment.